Nelson burr



iuilnd glatte NELSON BURR, OFI BA TVAVIA',

ILLINOIS.

Laim Parent No. 94,072; dared Augier 24,1869.

IMPROVEMENT IN @BINDING-MILLS *HOU-* The Schedule referred to in theseLetters Patent and making part of the same.-

To all whom 'it may concern:

Figm'e 1 represents the grinding-surface of the ring or disk.

Figure 2 designates thesaine form of grinding-surface with fig. 1, buton a reduced scale. d. lliigure 3 isa central vertical section of thering or 1s g Thev nature of my invention consists in the peculiarconstruction and dressing of cast-iron rings or disks, so as to adaptthem'for grinding corn or other grain, as set forth. y'

A represents a cast-iron disk or ring, an inch, more or less, in widthon' its face, and curved downward from the outer to the innercircumference. This curved surface is furnished with ve distinct seriesof grinding ridges.

The first series, marked a, is plane on the grinding side, slightlyconvex on the opposite side, andi nearly horizontal at its upper edge.The second series consists of ridges b, whic rextend from the periphery'of A inwarda quarter of n inch, more or less.

The third series c, extends from the periphery of the disk to more thanhalfof its width.

The fourth series' d, extends from the outer to the inner circumferenceof the disk A. l Thefifth series, marked e, has the same length andprominency with'a, but is slightlycurved at its upper edge.

It will be rcmarkedthat the upper and -lower disks are exactcounterparts or duplicates, and when ar- 'ranged in position fol:grinding, their respective ridges,

as above described, will cross each other at an angle similar to thatobserved in the dressing of ordinary millstones. y

It will be seen that thespace between the upper and lower' disks at theeye, will be sufliciently wide to receive all the corn that the diskshave the capacity to grind, and the grinding-capacityis greatlyincreased by therapidity with which the corn is reduced to meal, and thespeed witliwhich it is discharged into 'the meal-chest. l

As the grinding-plocess is carried 'on near the centre of motion, thereis a vgreat gain in power, and an increased rapidity of motion obtained.As a necessary consequence of rapid motion, the centrifugal force willbe so great as to expel the nieal instantly from between the disks, andthus prevent its heating or clog 1iing.

Experience having proved that a thousand revolutions `per minute impartno appreciable warmth to the meal, I claim to have-established aprinciple contrary to that generally received,^and to have provedsatisfactorily that the'mode to increase the capacity of a mill forgrinding corn is not to increase the grindingsurface, but to diminishit, asis exhibited by rings or disks.

Having thus described my invention,

What I claim, and desire to secure by Letters Patent, -sl Thecombination of the two similar grinding-disks,

here shown, each provided with the long ridges a and d, and theintervening shorter ridges-b and c, all constructed and airanged asherein set forth.

In testimony that I claim the foregoing as my own,

I aiiix my signature, in presence of two witnesses.

NELSON BURR.

Witnesses CHAs. C. STEPHENS, H. M. ARMSTRONG.

